February 13, 2013:

This project brings us to the Buena Vista neighborhood in San Francisco.  We’ll be replacing this wall with something much stronger.   A concrete wall is of course the most durable lasting 80 plus years but if budget is a factor, pressure treated (PT) timber is the way to go. But not all PT walls are constructed equally as you can see.  With the support post being the weakest link, failure occurs here in most instances.  Specifically, either the post rots out or the concrete footing will start destabilizing due insufficient depth and girth.

Day 1, old wall is removed and area excavated.

So how do you make a standard pressure treated 15 plus year wall into a 30 plus year wall?  More concrete and substitute pressure treated posts with steel I-beams.  Here you see the steel post dropped into a hole 4′ deep by 2′ wide.  1/2 cubic yard of concrete will secure the post for a very long time.

As we excavate the post holes, soil is loaded onto the trailer for dumping and concrete mix brought up.

All with five gallon buckets.  A typical San Francisco project due to limited access.

End of Day 3.

One very important process when working with pressure treated lumber is to seal all ends that have been cut.  When pressure treated material is manufactured, the chemical that protects it from rot, termites etc. is only injected about 20 percent into the surface ,at best.  Any cuts would leave that area open to intrusion of the elements.  Here we use “copper green” to seal it up.

Mira Drain.

Project Complete: February 2013, Buena Vista, San Francisco California.